Infectious diseases are defined as unhealthy conditions of the body or part thereof or the mind, which are caused by microorganisms such as bacteria, to viruses, rickettsiae, chlamydiae, mycoplasmas, fungi and protozoa. These microorganisms live on the skin, in the oral cavity, in the respiratory and gastrointestinal tracts, and in the genitalia, where they constitute normal flora. The interactions between the human hosts and pathogenic organisms are complex and dynamic and these interactions determine whether or not the microorganism remains apart from the human host, becomes part of the normal flora, or invades the host and causes disease.
According to the tissue tropism phenomenon, microorganisms selectively colonize specific body sites. These are called normal microbial flora and includes resident flora (which re-establishes itself if disturbed) and transient flora (which does not permanently establish itself). Commensal and symbiotic flora consists predominantly of bacteria and fungi. Furthermore, environmental factors including diet, sanitary conditions, air pollution and hygienic habits influence the species that constitute the normal microbial flora.
The host body is provided with various defence mechanism determining whether or not an infection will result, and these defence mechanisms include                1. natural barriers (e.g. skin and mucous membranes),        2. non-specific immune response factors (e.g. phagocytic cells, i.e. neutrophils and macrophages, and their products), and        3. specific immune response factors (e.g. antibodies).        
Only a small proportion of the microorganisms to which humans are exposed, produce infection and disease. This pathogenesis of infection includes:                1. toxins released by micro-organisms for interacting with host cells;        2. virulence factors for assisting host invasion and resist host defence mechanisms;        3. microbial adherence, i.e. the binding to surfaces to establish a base from which tissue penetration or cellular invasion is launched, and        4. viral virulence factors contribute to initiation and propagation of infection by viruses.        
The manifestations of infection include fever and systemic responses. Fever is defined as an elevation of body temperature above the normal daily variation, and includes pyrogens, febrile response, fever of unknown origin (FUO). Systemic responses are responses in various organ systems of the host as a result of an infection, and include hermatologic manifestations, cardiopulmonary manifestations, renal manifestations, hepatic manifestations, gastrointestinal manifestations, neurologic manifestations, endocrinologic and metabolic manifestations. The above facilitate the diagnosis of infections.
In order to prevent infections, the epidemiologic properties of the disease, the mode of transmission of the disease, and susceptibility of people to the disease have to be understood. In addition, immunobiologic agents are provided in the form of vaccinations, which include antigens or antibodies. Anti-infective pharmaceutical preparations are classified as antibacterial, antiviral, and anti-fungal drugs.
Combating of infectious diseases includes surveillance, analysis and control of the infectious diseases and in order to be effective, information is required to enable informed decisions by public health authorities, health and pharmaceutical researchers, politicians and persons infected by an infectious disease.
The acquisition of information is complicated due to various factors, such as lack of data, unreliable data as a result of manipulation and secrecy by governments, means for identifying relationships between acquired data, the complexity and non-linearity of infective transmission systems, the interactions between various diseases (infectious and non-infectious), the interactions between pharmaceuticals administered to combat infectious diseases, the epidemic nature of specific infectious disease, the vast number of factors influencing the working and spreading of infectious diseases, and the influence of legal issues such as patent protection of pharmaceuticals.
WO01/73427 discloses a method for analysing an infectious disease using computer based simulation engines, and includes the steps of simulating transmission of the infections disease using a first computer-based model and simulating the transmission of the infections disease using a second computer-based model. The method further includes the steps of analysing the transmission of the infections disease as a function of the first and second computer-based simulation engines.
US Patent Application 2001/0047125 A1 provides a method and apparatus for a wireless health monitoring system for interactively monitoring a disease or health condition of a patient by connecting an internet-enabled wireless web device to a health monitoring device which may be a medical device or other health related device such as an exercise machine. However, this is limited to the disease or health condition of a single patient and limited to a medical device or other health device.
It is an object of the invention to suggest an infectious disease surveillance system for identifying, studying the effects of and combating infectious diseases.